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fxus61 kaly 210259 
afdaly

Area forecast discussion
National Weather Service Albany New York
959 PM EST sun Jan 20 2019

Synopsis...
cold and blustery conditions for tonight and Monday with
dangerously cold wind chills, blowing snow, frigid temperatures
and gusty winds. The below normal temperatures will continue
into Tuesday, but winds should diminish by Tuesday afternoon, as
high pressure builds in over the northeast.

&&

Near term /until 6 am Monday morning/...
wind chill advisories and warnings are in effect for the
entire region from 6 PM this evening through 6 PM Monday...
Winter Storm Warning expired...

As of 9:58 PM, minor tweaks to first 12 hours of forecast based
on surface observations, radar and satellite imagery. No
significant changes.

Previous...
gusty northwest winds will blow snow around tonight with gusts
around 40 mph at times. There could be some lake effect thin
multi bands aimed into the western Mohawk Valley, Schoharie
valley and eastern Catskills tonight with maybe an inch of snow
tonight in some places. All areas should be cloudy tonight and
flurries are possible in all areas as the strong northern stream
upper low drops out of Canada into our region.

Temperatures will drop below zero in many areas and lower single
digits in the Mid Hudson valley and northwest CT. Wind chills will exceed
15 below zero in the southern half of the forecast area and exceed
25 below zero in the northern half of the area. Wind chill
advisories are in effect tonight and Monday.

Thanks to everyone for snow and ice measurements and we look forward
to more from those who still want to give US reports.

&&

Short term /6 am Monday morning through Wednesday/...
wind chill advisories and warnings are in effect for the
entire region from 6 PM this evening through 6 PM Monday...

Northern stream upper closed low tracks through New England and
offshore with some upper energy and moisture added to the lake
effect moisture, resulting in more clouds than sun on Monday and
some flurries and scattered snow showers. Winds will still be gusty
and there will be areas of blowing snow. The core of coldest air
will over the region and temperatures will reach the single numbers
in many areas but will remain below zero in northern areas and may
just barely exceed 10 degree in southern areas.

The low level ridging Will Park itself over our region late Monday
night and Tuesday morning with winds diminishing to near calm by
daybreak Tuesday. With snow pack in place, temperatures should fall
to or below the coldest temperature guidance, below zero in most
areas.

Warm advection begins later Tuesday but with light winds and the
weak January sun, highs Tuesday in the lower to mid 20s but teens in
the north and upper 20s in southern areas. Light south winds will
become steady through the Hudson Valley Tuesday night and low
temperatures will not be as cold as tonight and Monday night,
especially with some increasing and thickening mid and high clouds
in advance of the next system from the central and Southern Plains.
Some light precipitation is expected to spread northeast well
ahead of the system through the day Wednesday with some light snow,
transitioning through a mix of sleet and rain to rain in many areas
but a slower transition in northern areas, where a mix could occur
through Wednesday afternoon.

There are indications of boundary layer temperatures rising above
freezing and ageostrophic surface winds from the north and
northeast. With strong southwest boundary layer flow and surface
ageostrophic winds from the north, will have to keep an eye on
surface temperature trends as temperatures may not warm above
freezing much of the day in many areas if cold air is anchored and
southwest winds aloft cannot scour out the cold air. That would
result in the possibility of some freezing rain but it is too early
and the confidence level too low for a mention of freezing rain at
this time. Highs Wednesday in the 30s.

&&

Long term /Wednesday night through Sunday/...
active weather pattern continues into the first half of the weekend
as energetic waves and increasing amplification of the upper flow
evolves across North America.

Ridge over the western Atlantic is expected to amplify as upstream
vigorous jet dives southeastward from the northwest territories.
Inbetween will be a deep tropical moisture transport from the Gulf
of Mexico riding up the i95 corridor. Thermal profiles would
suggest a rain/snow mixture across the County Warning Area with more
rain in the capital district and points south and east. What is of
concern is the potential of moderate precipitation amounts on top of
frozen ground. This could complicate factors as air temperatures
may climb above freezing but ground temperatures not so much.
Regardless, it will be unsettled with a non-diurnal temperature
trend into Thursday morning.

Thursday, a general consensus from the global model suite suggests
the surface wave of low pressure tracks northeastward as the
transition back to winter precipitation types are expected. Cold
advection in the wake of the departing surface wave will bring an
end to the precipitation yet keep pops into the terrain as cyclonic
flow aloft remains in place.

Thursday night, seems a dry-slot will advect in between the
departing system and next upstream wave approaches. This is where
models diverge due to the fast movement of the upper synoptic flow
across noam. So per coordination, we will keep slight chance pops
for most of the region as overnight lows dip back below freezing.

Friday into Saturday, low confidence forecast as the ECMWF, GFS,
ggem while agree with digging trough into the mi-upr Mississippi
River valley and Great Lakes but surface low placement and quantitative precipitation forecast
differ significantly. So this leads US to place low chance pops
with mainly light snow.

&&

Aviation /03z Monday through Friday/...
light snow and flurries are diminishing and will continue in the
vicinity of kalb, kgfl and kpsf through about 04z. Blowing snow will
persist at kalb, kgfl and kpsf through about 11z. Ceilings will
hover between 2500-3500 feet through 04z then become predominant
above 3000 feet except for kpsf where ceilings will rise into the
VFR range after about 11z. Ceilings above 3000 feet will prevail
Monday morning and afternoon.

North to northwest winds will be 10 to 15 kt with gusts 25 to 35 kt
tonight through Monday morning and afternoon.

Outlook...

Monday night: moderate operational impact. Windy with gusts to 33.0
no sig weather.
Tuesday: no operational impact. No sig weather.
Tuesday night: low operational impact. Slight chance of snow.
Wednesday: high operational impact. Likely rain...sn...sleet.
Wednesday night: high operational impact. Definite rain...sn.
Thursday: high operational impact. Definite rain...sn.
Thursday night: low operational impact. Slight chance of shsn.
Friday: moderate operational impact. Chance of shsn.

&&

Hydrology...
very cold and mainly dry weather is expected Monday into
Tuesday. Another storm with snow or a wintry mix changing to
rain is expected Wednesday through Thursday, although precip
amounts and precip types are still uncertain at this time.

For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
advanced hydrologic prediction service /ahps/ graphs on our
website.

&&

Aly watches/warnings/advisories...
CT...Wind Chill Advisory until 6 PM EST Monday for ctz001-013.
New York...wind chill warning until 6 PM EST Monday for nyz032-033-
038>043-047-048-051-054-058-061-063-082>084.
Wind Chill Advisory until 6 PM EST Monday for nyz049-050-052-
053-059-060-064>066.
Massachusetts...wind chill warning until 6 PM EST Monday for maz001-025.
Vermont...wind chill warning until 6 PM EST Monday for vtz013-014.
Wind Chill Advisory until 6 PM EST Monday for vtz015.

&&

$$
Synopsis...snd/NAS

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